The Keeper of the Conscience of Marinus. This ancient machine was kept in a pyramid on an island, surrounded by a sea of acid. It generated pacifying waves that stopped the population from committing criminal activity. Worried that it might be misused, Arbitan had four of its vital keys hidden in locations around the planet. His fears proved justified, as a man named Yartek found a way to overcome its influence. His followers, the Voord, wanted to take over the machine to enslave all of Marinus to their will. Arbitan worked out how to make the Conscience effective once more, and so sent his friends off to find the keys in order to reset it. None returned - even his daughter Sabetha and her friend Altos. When the Doctor and his companions arrived on the island, Arbitan forced them to go in search of the keys - placing a force-field around the TARDIS to coerce them into complying.
Shortly after they had departed, using wristband travel dials, the Voord infiltrated the pyramid and murdered Arbitan.
When the travellers finally returned with the keys, Yartek pretended to be Arbitan - claiming he had been disfigured by a discharge from the machine. His scheme was seen through, and the use of a fake key killed him as well as destroying the Conscience. The Doctor told Sabetha that the people of Marinus should not need a machine to tell them the difference between right and wrong.
Played by George Couloris. Appearances: The Keys of Marinus (1964).
- It's quite a coup for the early days of Doctor Who - getting an actor who had appeared in that movie classic Citizen Kane.
- The dialogue is confusing about how old Arbitan is. He talks as if he built the Conscience, but it is supposed to have been running for centuries.
- And if Yartek and his Voords are the only people to have overcome the effects of the machine, why do the Doctor and his companions encounter so much villainy everywhere they go on the planet?